Second-harmonic microscopic observation of polarization reversal in "thresholdless" antiferroelectric liquid crystal

Abstract

In chiral tilted liquid crystals, various subphases emerge as a result of competition between ferroelectricity and antiferroelectricity. So far, the antiferroelectric phase with q_T=1/2 that exists in the mixture over a wide temperature range has been called the thresholdless antiferroelectric (TLAF) phase. SHG microscope observation of the polarization reversal process, however, revealed the existence of a threshold in the change of the SH image during the electric field sweep. Thus, this phase is not “TLAF” in the bulk.